Implantable active medical devices, such as cardiac disease rhythm management devices (pacemakers and defibrillators) and a variety of implantable muscle/nerve stimulators generally include a battery and battery-powered electronic pulse generator and may include a variety of sending, processing, and telemetry circuits all contained within a hermetically sealed housing or case and attached to a lead connector housing or block. The lead connector block is often affixed to the hermetically sealed housing with brackets, metal solder, and/or a medical grade adhesive.
Electronics within the hermetically sealed housing are conductively coupled to the lead connector block with an electrical feedthrough assembly. Electrical feedthroughs serve the purpose of providing a conductive path extending between the interior of a hermetically sealed container and a point outside the hermetically sealed housing. The conductive path through the feedthrough usually includes a conductor pin or terminal that is electrically insulated from the hermetically sealed housing. Feedthrough assemblies are known in the art to provide the conductive path and seal the electrical container from its ambient environment. Such feedthroughs include a ferrule, and an insulative material such as a hermetic glass or ceramic seal that positions and insulates the pin within the ferrule. Sometimes it is desired that the electrical device include a capacitor/filter within the ferrule and around the terminal, thus shunting any electromagnetic interference (EMI) and other high frequencies radiation at the entrance to the electrical device to which the feedthrough device is attached thereby preventing or substantially reducing EMI from entering the device. The capacitor electrically contacts the pin lead and the ferrule.
The pin lead/capacitor and capacitor/ferrule connection has been made using solder, weld, braze, and conductive adhesives. While this arrangement has proven to be highly reliable, it involves a variety of expensive manufacturing processes and parts that necessarily increase the cost of the resulting product.